First of all, IMAP server adress is wrong - your adress is a local one and Bitrix24 will not be adble to put a connection to it, please enter an IMAP server adress that will allow an access not only for your office (local), but a global one.

Second, please try to enter full login (full email) - it may or may not be necessary depending on the server's settings. We advise to try both ways.

I just answered another post which also asked about how to sync.I love using Bitrix24, and had the same problem at first (figuring out what to do) but the staff at Bitrix24 is very helpful so I got it sorted out quite fast.